The present invention relates in general to an artificial heart pump system, and, more specifically, to communication between a pump control unit worn by a patient and external units used by medical personnel to control heart pump operation and to collect patient and/or pump system performance-related data.
A heart pump system known as a left ventricular assist system (LVAS) is used for providing long term patient support with an implantable pump associated with an externally-worn pump control unit and batteries. The LVAS improves circulation throughout the body by assisting the left side of the heart in pumping blood. One such system is the DuraHeart® LVAS system made by Terumo Heart, Inc., of Ann Arbor, Mich. The DuraHeart® system employs a centrifugal pump with a magnetically levitated impeller to pump blood from the left ventricle to the aorta. The pump may be electronically controlled to provide a flow rate from two to eight liters per minute, for example. The desired flow rate depends on the size of the patient and the amount of assistance needed. The flow rate can also be varied in response to physiological changes of the patient.
An external unit (sometimes in the form of a hospital console), which is conventionally hard-wired to the externally-worn pump control unit, provides an interface for the health care professional to control the heart pump operation during setup and for subsequent adjustments. The external console unit also collects performance-related data from the pump control unit to verify 1) pump performance (e.g., the flow rate) and/or the condition of the patient. The monitored data may include pump conditions such as fault data that may be generated in the pump itself or patient conditions such as heart beat rate, blood pressure, or systemic resistance. The collected data is stored in the external console unit and can be analyzed by the health care professional to optimize the condition of the patient. The data may also be transferred by a hard-wired network connection from the external console unit to a centralized data management system for keeping track of status for a plurality of patients being cared for at a particular hospital ward, thereby allowing the health care professional to review the data for many patients at one convenient location.
Hard-wired communication provided by a cable between the pump control unit and the external console unit is desirable because of the security and reliability it provides. Interfering signals or misdirected control actions are not an issue for an isolated, hard-wired system. As another consequence, however, the patient must remain tethered to the external unit whenever communication is desired. Thus, times of patient mobility result in a lapse in the ability to monitor the pump operation.